Nuclear Explosion In A Blizzard

[snfaulkner]

I remember seeing some documentary footage (probably from the Atomic Museum in Vegas) that mentioned that they found that more damage was done to high-drag targets on hotter days since the shockwave travels at the speed of sound, which is faster at hotter temps. Not too sure how much of an effect there was tho, or how it would relate to not just a cold day, but with snow falling.

[HMS_Irruncible]

@snfaulkner

I remember seeing some documentary footage (probably from the Atomic Museum in Vegas) that mentioned that they found that more damage was done to high-drag targets on hotter days since the shockwave travels at the speed of sound, which is faster at hotter temps. Not too sure how much of an effect there was tho, or how it would relate to not just a cold day, but with snow falling.

That can’t be right. Shockwaves by definition travel faster than the speed of sound. Otherwise they’d be soundwaves. Soundwaves travel faster on cold days due to the density of the air. Am I wrong?

[snfaulkner]

@HMS_Irruncible

That can’t be right. Shockwaves by definition travel faster than the speed of sound. Otherwise they’d be soundwaves. Soundwaves travel faster on cold days due to the density of the air. Am I wrong?

From here

Temperature
T (°C) 	Speed of sound
c (m/s) 	Density of air
ρ (kg/m3) 	Characteristic specific acoustic impedance
z0 (Pa·s/m)
35 	351.88 	1.1455 	403.2
30 	349.02 	1.1644 	406.5
25 	346.13 	1.1839 	409.4
20 	343.21 	1.2041 	413.3
15 	340.27 	1.2250 	416.9
10 	337.31 	1.2466 	420.5
5 	334.32 	1.2690 	424.3
0 	331.30 	1.2922 	428.0
−5 	328.25 	1.3163 	432.1
−10 	325.18 	1.3413 	436.1
−15 	322.07 	1.3673 	440.3
−20 	318.94 	1.3943 	444.6
−25 	315.77 	1.4224 	449.1

[Stranger_On_A_Train]

@HMS_Irruncible

Sick burn, bro.

I didn’t mean that to be an insult. It is just when looking at phenomena like a nuclear detonation, trying to envision or make sense of the scale of the effect from experience is usually not possible, or make give a false impression. billfish678 is qualitatively correct; the snow (or rain, or even water laden air) will have a measurable attenuation on both the thermal and acoustic effects at distance, but the primary effects in the immediate blast zone won’t be substantially different.

Stranger

[HMS_Irruncible]

@Stranger_On_A_Train

I didn’t mean that to be an insult. It is just when looking at phenomena like a nuclear detonation, trying to envision or make sense of the scale of the effect from experience is usually not possible, or make give a false impression. billfish678 is qualitatively correct; the snow (or rain, or even water laden air) will have a measurable attenuation on both the thermal and acoustic effects at distance, but the primary effects in the immediate blast zone won’t be substantially different.

No, it’s like a pun on a thermal burn, and then you also won the thread science-wise. As usual. Cheers.

[snfaulkner]

BTW, upon further review,

Yes, The shockwave is indeed faster than sound. But the following blast winds will be approching sound, so the warmer the day, the faster the blast winds, the more damages to high drag targets.

[Lumpy]

@snfaulkner

BTW, upon further review,

Yes, The shockwave is indeed faster than sound. But the following blast winds will be approching sound, so the warmer the day, the faster the blast winds, the more damages to high drag targets.

But isn’t warm air less dense than cold air, and so has less momentum? Or does increased velocity more than make up for it?

[gnoitall]

@Lumpy

But isn’t warm air less dense than cold air, and so has less momentum? Or does increased velocity more than make up for it?

A6.1.1 Velocity pressure
The velocity pressure, which represents the kinetic energy per unit volume of the air flow, is the basic variable determining the wind loading on a building. It corresponds to the rise in pressure from the free stream (atmospheric ambient static pressure) to the stagnation point on the windward face of the building, and is defined as (1/2)ρU[sup]2[/sup], where U is the wind speed [and ρ is air density].

From http://www.aij.or.jp/jpn/symposium/2006/loads/Chapter6_com.pdf. (No particular preference for the Architectural Institute of Japan; it was just the first Google hit that returned the formula I was looking for.)

Anyway. Note the equation: The wind loading force is directly proportional to the density of air, but proportional to the square of wind speed. In other words, less density doesn’t cancel out higher wind speed.

In the end, I think it’s a wash, since the wind speed itself is derived from a pressure pulse which was affected at the outset by air density. Think of the wind shock as an energy transport mechanism from the bomb to the building. You won’t be getting more energy out of it than originally went into it. The only thing that might happen could be the relative fractions of energy transport (radiant v. shockwave v. wind blast) might vary from environment to environment.

[Leo_Bloom]

@HMS_Irruncible

…and then you also won the thread science-wise. As usual. Cheers.

Plus for “like comparing apples to Eskimos.” Which I never heard: did you coin that? (Especially because “Eskimos” and blizzards suggest each other.)

[billfish678]

@Stranger_On_A_Train

I didn’t mean that to be an insult. It is just when looking at phenomena like a nuclear detonation, trying to envision or make sense of the scale of the effect from experience is usually not possible, or make give a false impression. billfish678 is qualitatively correct; the snow (or rain, or even water laden air) will have a measurable attenuation on both the thermal and acoustic effects at distance, but the primary effects in the immediate blast zone won’t be substantially different.

Stranger

So it makes a difference where it makes a difference and it doesn’t where it doesn’t?

[billfish678]

@Leo_Bloom

A proper Fermi problem and solution in two senses. Nice.

Thanks.

Would be nice if someone found out just how MUCH snow is actually blowing around in a respectable blizzard.

Then you could do some actual calculations.

I worked at a place where stuff go blown up for fun and profit. There was actually an minor project to attenuate shock waves with large amounts of water droplets. Of course that spurred the creation of several silly Power Point slides involving sprinkers and various peoples cars.

Of course there will be some differences between a nuclear shock wave non nuclear one (at least out to a certain distance).

[Leo_Bloom]

@billfish678

Of course there are.

But they are in orange binders in safes and you need a security clearance to read them.

:dubious: Orange? How is it, one wonders, that you know that?

[Leo_Bloom]

In either event good sturdy outerwear is recommended.

[billfish678]

The universe is a mysterious place…

[Chronos]

Actual footage of over a hundred nuclear bombs being set off in Blizzard

[billfish678]

Well, at least you brought a simulation to the table…

[Machine_Elf]

@billfish678

I worked at a place where stuff go blown up for fun and profit. There was actually an minor project to attenuate shock waves with large amounts of water droplets. Of course that spurred the creation of several silly Power Point slides involving sprinkers and various peoples cars.

I think that’s pretty much what NASA used to do for the space shuttle launches. (video of test here)

[Hail_Ants]

I’m sure the Russians had ample opportunities, but offhand when & where did the US ever test a nuclear bomb in a blizzard? How could we have? We did our above ground tests in the South Pacific and the Nevada desert. AFAIK we never did above ground tests in an arctic-like climate. We set off a few in Alaska, but they were underground.